Method of working metal tubes



May 9, 1933.. .1. s ulREs METHOD or WORKING METAL TUBES Filed April 9. 1930 INVENTOR J0 Z1 71 fiyvz res. BY J/ TTORNEYS. V

Patented May 9, 1933 umrso STATES JOHN SQUIRES, OF HAG-EBSTOWN,

METHOD OI WORKING METAL TUBES Application filed. April 9,

This invention relates to a method of working metal tubes.

The main objects of this invention are to provide an improved method for supporting the inner walls of a metal tube to keep them from collapsing when subjected to the action of forming dies; and to provide an improved method by the use of which propeller blades of air foil sectionmay be formed from steel or other metal tubing.

' An illustrative embodiment of this invention is shown in the accompanying drawing,

which,

1 Fig. 1 is a longitudinal medial sectional view of a steel tube from which my improved propeller blade is made. 5

Fig. 2 is a similar view of the. same after the filler material has been put therein and the re stricting clamp secured on the open end there- Fig'. 3 is a view showing the tube in place between a pair of formin dies prior to the closing of the dies, the tu e being shown in section, as taken on'the line 3-3 of Fig. 2.

Fig. 4 is a similar view of the same after the forming dies have been brought together.

Fig. 5 is a sectional view taken on the line 55 of Fig. 1, looking in the direction indicated by-the arrows. The method disclosed herein is related to the method disclosed in my co-pending ap lication executed December 16, 1929, Serial 0.

. 415,028, filed December 18, 1929, and the type of blank from which the propeller blade is made is of the character which has been formed in accordance with the method disclosed in my co-pending application executed .of even date herewith, Serial No. 442,949, filed April 9, 1930. It will be understood, however, that this method is equally applicable for use in'the working of other types of blanks regardless of the manner in which they were formed, and by the term metal tube as used any hollow metal body without regard to its cross sectional shape or general conformation. In the embodiment shown in the drawing,

, an elongated seamless tapered steel tube 6 having a closed end 7 and an outwardly extending annular bead or flange 8 is provided with a in the specification and claims herein is meant 1930. Serial in. 442,950.

split clamping ring 9 secured thereon by bolts 10. The ring 9 embraces the head 8 and is provided with an inwardly extending annular flange 11 which provides a restricted opening therethrough for the open end of the tube 6..

The tube 6 with the clamp 9 thereon is placed in an, inverted position from that shown in Fig. 2 of the drawing, and filled with molten resin or other non-ductile solidifiable liquid integral mass which will harden or solidify at normal atmos heric temperatures.

The filled .tube' is t en placed between a pair of forming dies 12 and 13 which have die de ressions 14 and 15 respectively there- --in. he perimetric distance of the die depressions 14 and 15 is equal to the circumference of the tube 6 so that when the dies are brought together the walls of the tube will not be stretched.

The dies 12 and 13 are tlien brought togetheras shown in Fig. 4 of the drawing, thus squeezing or pressing the opposite sides of the tube 6 toward each other to secure an airfoil cross section of the tube. As the walls of the tube are forced toward each other a part of the filler mass 16 is squeezed out through the restricted opening formed by the flange 11, the resistance being such, however, that the walls of the tube are eifectually supported during theforming movement of the dies, and caused to be pressed out to the exact conformation of the die depressions. 4

- After the forming operation has been completed the clamp 9 is removed from the bead 8 and the resin melted out of the formed propeller blade. 1 Although but one specific method has been herein disclosed, it will be understood that o numerous details thereof may be altered or omitted, without departing from the spirit of this invention as defined by the following claims.

What I claim is:

1. The method of working a metal tube which comprises filling the tube with resin, and then subjecting the tube to the action 7 of .forming dies'for changing the cross-sectional shape of the tube.

, 2. The method of working a' metal tube which comprises filling the tube with molten resin, solidifying the resin, and then subecting the tube to the action of forming dies for ch tube.

3. The method of working a metal tube anging the cross-sectional shape of the which comprises fillingth tube with resin,

subjecting the tube to the action of forming dies for changing the, cross-sectional shape of the tube, and then removing the resin.

which comprises filling the tube with molten resin, solidifying the resin, subjecting. the tube to the action of forming dies for chang; ing the cross-sectional shape of the tube, and then melting out the resin.

5. The method of shaping an open-ended metal tube which comprises restricting the opening in the end of the tube, tube with resin, and then subjecting the tube to the action of forming dies for changing the cross-sectional shape of thetube.

6. The method of shaping an open-ended metaltube which comprises restricting the opening in the end of the tube, filling the tube with molten resin, and then subjecting the tube to the action changing the cross-sectional shape of the filling the tube.

7. The method of shaping an open-ended metal tube which comprises restricting the opening in the end of the tube, filling the tube with resin. sub ecting the tube to the action of forming dies, for changing the cross-sectional shape of the tube, and then removing the filler mass.

8. The method of shaping an open-ended metal tube which comprises restr cting the opening in the endof the tube, filling the tube with molten resin, solidifying the resin, subjecting the tube to the action of forming dies for changing the of the tube, and then mass.

JOHN SQUIRES.

4. The method of working a metal tubeof forming dies for cross-sectional shape 7 melting out the filler 

